Reallocating crop rotation patterns improves water quality and maintains crop yield
Reallocating crop rotation patterns improves water quality and maintains crop yield
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DOI：
10.1016/j.agsy.2020.103015
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发表时间：
2021-02-01
影响因子：
6.6
通讯作者：
Veith, Tamie L.
中科院分区：
文献类型：
--
作者：
Jiang, Fei;Drohan, Patrick J.;Veith, Tamie L.
满足社会日益增长的粮食生产需求，同时保持或改善水质，是世界各地许多流域面临的挑战。在许多国家，农业规范是由农民根据市场需求和个体农业企业最经济有效地利用土地资源来决定种植什么、何时和何地。作为一种替代办法，欧洲联盟（欧盟）探讨了以土壤为基础的土地利用框架的潜力，以实现农业为主的流域的经济和环境目标，但是，这一框架尚未在美国（美国）探索。我们调查了欧盟风格的土壤为基础的，土地利用框架，以改善水质，同时保持作物产量的潜力，在子流域的切萨皮克湾。利用土壤和水资源评估工具（SWAT）模拟作物生长以及8年（2010 - 2017）的总氮（TN），总磷（TP）和沉积物损失。基于SWAT模型的结果，开发了一种算法，在空间上重新分配现有的农业用地内的作物轮作，以减少TN，TP和泥沙流失的土壤性质的基础上，同时保持类似的生产面积的每个旋转。干草被重新分配到最容易受到侵蚀和养分流失的景观，而玉米-大豆轮作被重新分配到不太脆弱的地区。在重新分配的情景中，28%的农业用地保留了与基线情景相同的作物轮作，而72%被重新分配。在SWAT模拟的重新分配的情况下，TN，TP和泥沙流失减少了15%，14%和39%，分别在年均尺度。这些结果表明，即使没有额外的结构性最佳管理实践，在受损流域内简单地重新分配作物轮作也可以显着改善水质。虽然这里评估了流域规模的效益，但需要进一步研究，以了解这种方法如何影响农场一级的因素，因为实施可能需要一些农民改变他们种植的作物类型。
Meeting the growing food production needs of a society, while simultaneously maintaining or improving water quality, is a challenge facing many watersheds around the world. Across many nations, the agricultural norm is for farmers to dictate what, when and where to plant based on market demand and the most economically efficient use of land resources for the individual farm enterprise. As an alternative, the European Union (EU) has explored the potential of a soil-based, land use framework to achieve economic and environmental targets in agriculturally dominated watersheds; however, this framework has not been explored in the United States (US). We investigated the potential for an EU style soil-based, land use framework to improve water quality, while maintaining crop yields, in a sub-watershed of the Chesapeake Bay. The Soil and Water Assessment Tool (SWAT) was utilized to model crop growth, and losses of total nitrogen (TN), total phosphorus (TP) and sediment for an 8-year period (2010 - 2017). Based on SWAT model results, an algorithm was developed to spatially reallocate crop rotations within existing agricultural land to reduce TN, TP, and sediment losses based on soil properties while maintaining a similar production area of each rotation. Hay was reallocated onto landscapes most vulnerable to erosion and nutrient loss, whereas corn-soybean rotations were reallocated onto less vulnerable areas. In the reallocated scenario, 28% of agricultural lands retained the same crop rotation as the baseline scenario while 72% were reassigned. In a SWAT simulation of the reallocated scenario, TN, TP and sediment losses were reduced by 15%, 14% and 39%, respectively at an average annual scale. These results suggest that simply redistributing crop rotations within an impaired watershed can make significant water quality improvements even without additional structural best management practices. Although watershed-scale benefits were evaluated here, future research is needed to understand how this approach affects farm-level factors, as implementation may require some farmers to change the type of crops they grow.